Redetachable, self-adhesive device

ABSTRACT

Redetachable, self-adhesive device having a plate, the sides and/or front side of which have fastening means, if appropriate, and the rear side of which has a strip of an adhesive film which is adhesive on both sides and is adhesively attached in such a way that one end of the adhesive film protrudes beyond the plate as a grip, the adhesive film being of such a kind that the adhesive bond achieved with it can be released again by pulling in the direction of the bonding plane, stretching the strip, characterized in that the rear side of the plate ( 1 ) has laterally alongside the adhesively attached adhesive film ( 5 ) spacers ( 3 A,  3 B), the height of which is less than the thickness of the adhesive film ( 5 ).

This application is a division of U.S. Ser. No. 09/249,710, which is nowpending which is a Div of Ser. No. 08/924,788 filed Sep. 5, 1997, nowU.S. Pat. No. 5,928,747.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a redetachable, self-adhesive device which canbe released again from its adhesive bond without leaving any residue bypulling on the adhesive film, arranged on it, in the direction of thebonding plane. In particular, the invention relates to a plate of thistype, on which other things can be fastened if appropriate, or whichitself is designed as a hook or the like if appropriate.

2. Description of Related Art

Such devices, in particular hooks, are known. For instance, DE 42 33 872C2 describes a redetachable, self-adhesive hook which is equipped withan adhesive film which can be adhesively released by pulling and whichis commercially available as “tesa® Power-Strips with Hooks”. Aso-called system hook with base plate and attachable decorative hook isalso commercially available as the tesa® Power Strip System Hook.

WO 94/21157 also discloses such a hook, which differs from theabovementioned hook in particular by the use of an adhesive film of thekind which is highly extensible and at the same time does not recoverits original form.

In the practical use of such devices, problems may occur, however, inparticular during later detachment.

What is particularly disadvantageous about the previously known problemsolutions is that the releasing of the adhesive bond has to take placeby pulling the adhesive strips substantially in the bonding plane,errors in use being inevitable for the unexperienced user.

In many cases it has been found that tears are caused by the userexerting considerable force to press the item to be released against theobject to which it is adhesively bonded during the releasing process. Asa result, the force necessary for pulling the adhesive tape out of theadhesive joint is increased to such an extent that the tearingresistance is exceeded, with the unfortunate consequence for the userthat the adhesive tape tears and the adhesive bond can no longer bereleased non-destructively and without leaving any residue.

The object of the invention was to overcome the aforementioneddisadvantages.

SUMMARY OF THE INVENTION

This object is achieved by means of a device such as that characterizedin more detail in the claims. Accordingly, the invention relates to:

A redetachable, self-adhesive device having a plate, the sides and/orfront side of which have fastening means, if appropriate, and the rearside of which has a strip of an adhesive film which is adhesive on bothsides and is adhesively attached in such a way that one end of theadhesive film protrudes beyond the plate as a grip, the adhesive filmbeing of such a kind that the adhesive bond achieved with it can bereleased again by pulling in the direction of the bonding plane,stretching the strip, characterized in that the rear side of the plate(1) has laterally alongside the adhesively attached adhesive film (5)spacers (3A, 3B), the height of which is less than the thickness of theadhesive film (5).

In particular a device according to Claim 1, characterized in that thespacers (3A, 3B) are located on both sides alongside the adhesivelyattached adhesive film (5).

In particular a device according to Claim 1, characterized in that thespacers (3A, 3B) are formed as fillets or segments.

In particular a device according to Claim 1, characterized in that thespacers (3A, 3B) are arranged on both sides and, on each of these sides,at least in the region of the two ends.

In particular a device according to Claim 1, characterized in that it isformed as an injection-moulded part of plastic.

In particular a device according to Claim 1, characterized in that theheight of the spacers (3A, 3B) is 35-90% of the thickness of theadhesive film (5), in particular is 0.3-0.6 mm in the case of athickness of the adhesive film (5) of 0.65 mm.

In particular a device according to Claim 1, characterized in that theadhesive film (5), with or without an intermediate substrate, iselastically or plastically extensible.

In particular a device according to Claim 1, characterized in that theadhesion of the adhesive film (5) is less than the cohesion, theadhesiveness is dissipated to a great extent when the film is extended,and the ratio of pulling-off force to tearing load is at least 1:1.5,the adhesive film being of the kind which is based on thermoplasticrubber and tackifying resins, with high elasticity and low plasticity.

In particular a device according to Claim 1, characterized in that therear side of the adhesive film (5) is covered with a release laminate,such as a siliconized release paper or a release film.

In particular a device according to Claim 1, characterized in that atthe sides of the plate (1) there are engaging devices (4) into which acorresponding hook or the like can be engaged.

DETAILED DESCRIPTION OF THE INVENTION

The height of the spacers is advantageously chosen such that it is lessthan the thickness of the (unstretched) adhesive film, so that asatisfactory adhesive bond with the adherent surface is possible. Theextension of the adhesive film occurring during the detachment operationcauses the said film to be reduced correspondingly in width andthickness. If the thickness of the adhesive film reached duringdetachment is less than the height of the spacers, detachment of theadhesive film without tearing is even possible if high contact pressuresoccur at the same time vertically to the adhesive bond, which wouldotherwise have lead to tearing of the adhesive tape.

According to the invention, suitable in particular as adhesive films arethose corresponding to DE 33 31 016, DE 42 22 849, DE 42 33 872, WO92/11333 and WO 94/21157.

For instance, DE 33 31 016 A 1 describes an adhesive film forre-releasable adhesive bonds which allows an adhesive bond establishedtherewith to be released by pulling on the adhesive film in thedirection of the bonding plane. With such adhesive films, high adhesiveforces and shear strengths can be achieved and adhesive bonds can bereleased again without further aids, in a way comparable to the openingof a preserving jar, similar to the way in which there the rubber sealis pulled by the grip out of the seal joint.

DE 42 22 849 C 1 describes such an adhesive film with a UV-impermeablegrip.

WO 92/11333 also describes, inter alia, adhesive films for correspondingapplications, the adhesive films used having a low elasticity with atthe same time high extension.

Double-sided self-adhesive tapes with a foam intermediate substrate, forexample of polyethylene foam, can also be used according to theinvention.

In general, for production, processing and handling of the particularlypreferred adhesive films, reference is made to DE 33 31 016, DE 42 22849 and WO 92/11333.

Suitable as the material for the plate or moulding, in particular forbase plates, are:

Plastic, metal, wood (coated, for example painted, and uncoated),ceramic and the like.

Devices according to the invention serve for receiving one side of theadhesive film, the other side of which is adhesively bonded onto theselected under-lying surface. A wide variety of adapters, including hookbodies, can be placed onto the device or plate. To produce a highbonding strength, the surface of the plate on the side to which theadhesive film is applied consists in particular of a material which hasan adhesion with respect to the adhesive film which is adequate for therespective application. When using contact adhesives based on styreneblock copolymers or acrylate copolymers, advantageously used in thiscase are, inter alia, polystyrene, impact-modified polystyrenes, PMMA,aromatic polyesters, polycarbonate or polyamide.

To accomplish a pulling-off behaviour without tearing, even under theeffect of high forces acting perpendicularly with respect to the bondingplane (for example caused by high contact pressure when releasing theadhesive bond), the plate is equipped with spacers (for examplefillets), as still to be described in detail, on the side which bearsthe adhesive film.

Spacers may be provided on both sides alongside the adhesive film overthe entire length of the base plate, or else only in certain subregionsthereof. Specific formations, right-angled fillet-like, rounded-offfillet-like, punctiform etc., are possible. A spacer may be arranged atone of the end faces on the rear side of the plate (1) alongside theadhesively attached adhesive film strip (5).

Tests with different redetachable adhesive films show that, depending onthe type and structure of the adhesive films used, typical strippingextensions lie between 100% and 800%. In practice, it is found that, inthe case of substantially rubber-elastic adhesive films, the height ofthe spacers should be at least about 0.05 mm, preferably 0.10 mm, higherthan the thickness of the stretched adhesive films during the detachmentprocess. For a reliable adhesive bond, on the other hand, the spacerheight should be kept about 0.05 mm, preferably 0.1 mm, particularlypreferably 0.15 mm, less than the thickness of the adhesive films in thenon-stretched state. The values specified relate to planar, solidadherent surfaces. In the case of rough and/or slightly deformableadherent surfaces, values higher than those quoted may be advisable bothfor a satisfactory bonding process (adequate contact pressure) and forsatisfactory redetachment.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is to be explained in more detail below with reference toexemplary embodiments, without however wishing to restrict itunnecessarily. In the drawing:

FIG. 1 shows an obliquely lateral view of a device according to theinvention,

FIG. 2 shows a side view according to FIG. 1, with an adhesivelyattached adhesive film strip,

FIG. 3 shows an end view according to FIG. 1,

FIG. 4 shows a side view according to FIG. 2, the device beingadhesively attached by its adhesive film strip to an object, and

FIG. 5 shows an end view according to FIG. 4.

To be specific, FIG. 1 shows a plate 1 with a rear side 2, which servesfor receiving a strip of double-sided adhesive film and has spacers 3A,3B in the form of fillets to the sides of the adhesive film to beadhesively attached. On its sides, the plate 1 also has engaging devices4, into which a corresponding device can engage, for instance a platewith a hook or some other fastening device, as is standard andcommercially available.

FIG. 2 shows how a strip 5 of an adhesive film is adhesively attached tothe plate 1, it being indicated by the dotted line 6 how the spacers 3Aand 3B partially enclose the strip 5 to the sides, while one end of theadhesive film protrudes beyond the plate 1 as a grip 7. In FIG. 3, as anend view of the plate 1, the latter is represented with the spacers 3A,3B and also with the engaging devices 4.

FIG. 4 shows in a lateral view how such a device is adhesively attachedto an object 8, for instance a wall, a door or a cupboard, with plate 1,strip 5 of an adhesive film, the grip 7 protruding beyond one end of theplate 1, the grip 7 being made non-adhesive by thin films 9A, 9B. InFIG. 5, this arrangement is represented in an end view, with plate 1,strip 5 of an adhesive strip, and also spacers 3A, 3B which laterallyenclose the strip 5 and extend to about half the thickness of the strip5.

EXAMPLE

For a single-layer adhesive film of the following formulation:

50 parts of Foralyn 110 (Hercules), 50 parts of Vector 4211 (ExxonChemical), 0.5 parts of Irganox 1010 (Ciba)

of a thickness of 650 μm, a maximum tensile force of 52 N/cm,corresponding to 8.0 MPa, and an ultimate elongation of 1300% aredetermined.

Rectangular pieces of the adhesive film measuring 20 mm×50 mm areadhesively bonded centrally to base plates consisting of steel of thedimensions 3 mm×40 mm×22 mm (height×length×width) in such a way that thebase plates are covered on one side over their entire length by theadhesive film and a 10 mm long strip of adhesive film protrudes beyondone of the short sides of the base plate, which can be used as a gripfor later detachment. The base plates are provided on both longitudinaledges on the side to which the adhesive films are applied with spacers0.5 mm wide and of different heights. The base plates provided withadhesive films are adhesively bonded onto a planar underlying surface ofResopal. For this purpose, the base plates provided with the adhesivefilms are applied flatly to the underlying Resopal surface and pressedonto it with 500 N for 5 seconds. In a second operation, for detachingthe adhesive films, the test pieces fixed in this way are subjected to aforce of likewise 500 N, acting vertically onto the bonding plane, andthen the adhesive film strip is pulled out of the adhesive joint at anangle of <10° with respect to the bonding plane. For comparison, thetests are carried out without any force acting vertically on the bondingplane. The stripping rate in all the tests is about 1000 mm/min. Thefollowing results are obtained.

Vertical pressing Without vertical Height of the spacers force 500 Nforce No spacer Strip tears Can be detached without tearing 0.3 mm Canbe detached Can be detached without tearing without tearing Strippingforce* 10//14 N/cm 0.4 mm Can be detached Can be detached withouttearing without tearing Stripping force* 9//15 N/cm 0.5 mm Can bedetached Can be detached without tearing without tearing Strippingforce* 9//10 N/cm 0.6 mm Can be detached Can be detached without tearingwithout tearing Stripping force* 9//10 N/cm 0.7 mm No adhesive Noadhesive bonding possible bonding possible *Mean value//maximum value(the maximum value is reached at the end of the stripping operation).

Under the chosen test conditions, only base plates provided with spacerscan be detached again without tearing under the effect of high verticalforces acting on the base plate.

What is claimed is:
 1. A releasable, self-adhesive device comprising: a)a plate having a front, a rear and four sides; and b) a double-sidedadhesive strip of film adhered to the rear of said plate through anadhesive bond in such a way that one end of said adhesive film stripprotrudes from said plate as a grip; wherein the adhesive bond betweensaid adhesive film strip and said plate can be released by pulling andstretching the adhesive film strip; and spacers are arranged on bothsides on the rear of said plate alongside the adhesively attachedadhesive film strip, said spacers extending less than the entire lengthof said plate, and said spacers projecting from the rear of said plateto a height that is less than the thickness of said adhesive film strip.2. Device according to claim 1, wherein the spacers are formed asfillets or segments.
 3. Device according to claim 1, wherein the spacersare arranged on both sides and, on each of these sides, at least in theregion of the two ends.
 4. Device according to claim 1, which is formedas an injection-moulded part of plastic.
 5. Device according to claim 1,wherein the height of the spacers is 35-90% of the thickness of theadhesive film strip.
 6. Device according to claim 1, wherein theadhesive film strip, with or without an intermediate substrate, iselastically or plastically extensible.
 7. Device according to claim 1,wherein the adhesion of the adhesive film strip is less than thecohesion, the adhesiveness is to a great extent dissipated when the filmis extended, and the ratio of pulling-off force to tearing load is atleast 1:1.5, the adhesive film being of the kind which is based onthermoplastic rubber and tackifying resins, with high elasticity and lowplasticity.
 8. Device according to claim 1, wherein the rear side of theadhesive film strip is covered with a release laminate.
 9. Deviceaccording to claim 1, wherein at the sides of the plate there areengagement devices into which a corresponding hook can be engaged. 10.Device according to claim 1, wherein a spacer is arranged at one of theends on the rear side of the plate alongside the adhesively attachedadhesive film strip.
 11. Device according to claim 5, wherein the heightof the spacers is 0.3-0.6 mm and the thickness of the adhesive filmstrip is 0.65 mm.
 12. Device according to claim 8, wherein the releaselaminate is a siliconized release paper or a release film.
 13. Deviceaccording to claim 1, wherein the spacers have a rounded-off shape. 14.Device according to claim 9, further comprising a hook engaged with saidengagement devices.
 15. A method of forming a temporary bond between asubstrate and a device according to any one of claims 2-10, 1, and11-14, which bond can be released easily and without residue, saidmethod comprising adhering said device to said substrate by means of anadhesive bond formed between said substrate and said adhesive filmstrip, and thereafter releasing said device from said substrate bypressing said plate and said adhesive film strip against said substrateand pulling on the grip of said adhesive film strip at an angleapproximately perpendicular to the plane of the bond formed between saidsubstrate and said adhesive film strip.
 16. A self-adhesive device fordetachable adhesive bonding onto an underlying surface, comprising: aplate having a rear side, the rear side having at least one spacerextending less than the entire length of said plate and a planarsurface; a strip of double-sided adhesive film adhesively attached tosaid planar surface, one end of the adhesive film protruding beyond theplate as a grip; and at least one engaging device disposed on the platefor engaging an adapter; wherein the spacer height is less than thethickness of the adhesive film an adhesive bond between said adhesivefilm and said plate can be released by pulling on the adhesive film inthe direction of the plane of said bond.
 17. The device of claim 16wherein the rear side has two ends, a spacer being disposed at one end,and said grip protruding beyond the other end.
 18. The device of claim16 wherein the adhesive film has a foam intermediate substrate.
 19. Thedevice of claim 17 wherein the adhesive film has a foam intermediatesubstrate.
 20. The device of claim 16, 17, 18 or 19 further comprisingan adapter engaged to the plate.
 21. The device of claim 20 wherein theadapter is a fastening device.
 22. The device of claim 21 wherein thefastening device is a hook.
 23. The device of claim 17 wherein thespacer has a rounded-off shape.
 24. The device of claim 16 or 17 whereinthe plate is formed of plastic.
 25. The device of claim 16 or 17 whereinthe adhesive film can be detached by pulling without tearing.
 26. Amethod of forming a temporary bond between a substrate and a deviceaccording to any one of claims 16-25, which bond can be released easilyand without residue, said method comprising adhering said device to saidsubstrate by means of an adhesive bond formed between said substrate andsaid adhesive film strip, and thereafter releasing said device from saidsubstrate by pressing said plate and said adhesive film strip againstsaid substrate and pulling on the grip of said adhesive film strip at anangle approximately perpendicular to the plane of the bond formedbetween said substrate and said adhesive film strip.
 27. A device forremovably, adhesively attaching to a support surface, comprising: a basemember having a bottom surface and a mount for releasably engaging withan adapter; a stretch release double-sided adhesive strip disposablebetween the bottom surface and the support surface; and at least onespacer disposed on the bottom surface of the base member for engagingthe support surface when the base member is urged in the direction ofthe support surface, the height of the spacer being less than thethickness of the adhesive film, and said spacer extending less than theentire length of said base member.
 28. The device according to claim 27,further comprising an adapter.
 29. The device according to claim 28,wherein the base member has two ends and wherein the adhesive strip isconfigured to extend beyond one end and to be grippable when the adapteris disengaged to stretch the adhesive strip.
 30. The device according toclaim 29, wherein the adapter is a hook body.
 31. The device accordingto claim 27, wherein the base member is a molded plastic member.
 32. Thedevice according to claim 28, 29, 30 or 31, wherein the spacer is anabutment.
 33. The device according to claim 32, wherein the adhesivestrip has a foam intermediate substrate.
 34. The device according toclaim 33, wherein the adhesive strip releases from the support surfacewhen stretched without leaving a residue on the support surface.
 35. Amethod of forming a temporary bond between a substrate and a deviceaccording to any one of claims 27-34, which bond can be released easilyand without residue, said method comprising adhering said device to saidsubstrate by means of an adhesive bond formed between said substrate andsaid adhesive film strip, and thereafter releasing said device from saidsubstrate by pressing said base member and said adhesive film stripagainst said substrate and pulling on the grip of said adhesive filmstrip at an angle approximately perpendicular to the plane of the bondformed between said substrate and said adhesive film strip.